In humans, ATRN is a candidate gene for sporadic amyotrophic lateral sclerosis (Morahan et al., 2009), ATRN plasma levels are altered in early-onset Alzheimer’s disease (AD) patients prior to symptoms (Muenchhoff et al., 2016), and its gene expression is reduced in Parkinson disease (PD) patients (Glaab and Schneider, 2015). The gene discussed is ATRN; the disease is Parkinson disease.